package cnu.cse.crawler.utils;

/*
 * Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Sun Microsystems nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import java.io.*;
import java.net.URL;

import java.security.*;
import java.security.cert.*;

import javax.net.ssl.*;

public class InstallCert {

	public InstallCert()
	{
		
	}
	
    public void install(String[] args) throws Exception 
    {
    	String host;
    	int port;
    	char[] passphrase;
    	
    	if ((args.length == 1) || (args.length == 2)) 
    	{
    		String[] c = args[0].split(":");
    		host = c[0];
    		port = (c.length == 1) ? 443 : Integer.parseInt(c[1]);
    		String p = (args.length == 1) ? "changeit" : args[1];
    		passphrase = p.toCharArray();
    	} 
    	else 
    	{
    		System.out.println("Usage: java InstallCert <host>[:port] [passphrase]");
    		return;
    	}

    	File file = new File("jssecacerts");
    	if (file.isFile() == false) 
    	{
    		char SEP = File.separatorChar;
    		File dir = new File(System.getProperty("java.home") + SEP + "lib" + SEP + "security");
    		file = new File(dir, "jssecacerts");
    		
    		if (file.isFile() == false) 
    		{
    			file = new File(dir, "cacerts");
    		}
    	}
	
    	System.out.println("Loading KeyStore " + file + "...");
    	InputStream in = new FileInputStream(file);
    	KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
    	ks.load(in, passphrase);
    	in.close();

    	SSLContext context = SSLContext.getInstance("TLS");
    	TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
    	tmf.init(ks);
    	X509TrustManager defaultTrustManager = (X509TrustManager)tmf.getTrustManagers()[0];
    	SavingTrustManager tm = new SavingTrustManager(defaultTrustManager);
    	context.init(null, new TrustManager[] {tm}, null);
    	SSLSocketFactory factory = context.getSocketFactory();

    	System.out.println("Opening connection to " + host + ":" + port + "...");
    	SSLSocket socket = (SSLSocket)factory.createSocket(host, port);
    	socket.setSoTimeout(10000);
    	
    	try 
    	{
    		System.out.println("Starting SSL handshake...");
    		socket.startHandshake();
    		socket.close();
    		System.out.println();
    		System.out.println("No errors, certificate is already trusted");
    	}
    	catch (SSLException e) 
    	{	    
    		System.out.println();
    		e.printStackTrace(System.out);
    	}

    	X509Certificate[] chain = tm.chain;
    	if (chain == null) 
    	{
    		System.out.println("Could not obtain server certificate chain");
    		return;
    	}

    	BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

    	System.out.println();
    	System.out.println("Server sent " + chain.length + " certificate(s):");
    	System.out.println();
    	MessageDigest sha1 = MessageDigest.getInstance("SHA1");
    	MessageDigest md5 = MessageDigest.getInstance("MD5");
    	for (int i = 0; i < chain.length; i++) 
    	{
    		X509Certificate cert = chain[i];
    		System.out.println(" " + (i + 1) + " Subject " + cert.getSubjectDN());
    		System.out.println("   Issuer  " + cert.getIssuerDN());
    		sha1.update(cert.getEncoded());
    		System.out.println("   sha1    " + toHexString(sha1.digest()));
    		md5.update(cert.getEncoded());
    		System.out.println("   md5     " + toHexString(md5.digest()));
    		System.out.println();
    	}

    	System.out.println("Enter certificate to add to trusted keystore or 'q' to quit: [1]");
    	String line = reader.readLine().trim();
    	int k;
    	try 
    	{
    		k = (line.length() == 0) ? 0 : Integer.parseInt(line) - 1;
    	} 
    	catch (NumberFormatException e) 
    	{
    		System.out.println("KeyStore not changed");
    		return;
    	}

    	X509Certificate cert = chain[k];
    	String alias = host + "-" + (k + 1);
    	ks.setCertificateEntry(alias, cert);

    	OutputStream out = new FileOutputStream("jssecacerts");
    	ks.store(out, passphrase);
    	out.close();

    	System.out.println();
    	System.out.println(cert);
    	System.out.println();
    	System.out.println("Added certificate to keystore 'jssecacerts' using alias '" + alias + "'");
    }
    
    private static final char[] HEXDIGITS = "0123456789abcdef".toCharArray();

    private static String toHexString(byte[] bytes) 
    {
    	StringBuilder sb = new StringBuilder(bytes.length * 3);
    	for (int b : bytes) 
    	{
    		b &= 0xff;
    		sb.append(HEXDIGITS[b >> 4]);
    		sb.append(HEXDIGITS[b & 15]);
    		sb.append(' ');
    	}
	
    	return sb.toString();
    }

    private static class SavingTrustManager implements X509TrustManager 
    {
    	private final X509TrustManager tm;
    	private X509Certificate[] chain;

    	SavingTrustManager(X509TrustManager tm) 
    	{
    		this.tm = tm;
    	}

    	public X509Certificate[] getAcceptedIssuers() 
    	{
    		throw new UnsupportedOperationException();
    	}

    	public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException 
    	{
    		throw new UnsupportedOperationException();
    	}

    	public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException 
    	{
    		this.chain = chain;
    		tm.checkServerTrusted(chain, authType);
    	}
    }
}